GILA HOT SPRINGS, N.M. — Micah True went off alone on a Tuesday morning to run through the rugged trails of the Gila Wilderness, and now it was already Saturday and he had not been seen again.

The search for him, once hopeful, was turning desperate. Weather stoked the fear. The missing man was wearing only shorts, a T-shirt and running shoes. It was late March. Daytimes were warm, but the cold scythed through the spruce forest in the depth of night, the temperatures cutting into the 20s.

For three days, rescue teams had fanned out for 50 yards on each side of the marked trails. Riders on horseback ventured through the gnarly brush, pushing past the felled branches of pinyon-juniper and ponderosa pine. An airplane and a helicopter circled in the sky, their pilots squinting above the ridges, woodlands, river canyons and meadows.

“We’re in the middle of nowhere, and this guy could be anywhere,” Tom Bemis, the rescue coordinator appointed by the state police, said gloomily. He was sitting in a command center, marking lines on a map that covered 200,000 acres. Some 150 trained volunteers were at his disposal, and dozens of others were there too, arrived from all over the country, eager and anxious, asking to enlist in the search.

“Coming out of the woodwork,” Bemis said wryly.

Not only did Micah True have loyal friends, but he also had a devoted following. At age 58, he was a mythic figure, known by the nickname Caballo Blanco, or White Horse. He was a famous ultrarunner, competing in races two, three or four times as long as marathons. The day he vanished, he said he was going on a 12-mile jaunt, for him as routine as a lap around a high school track.

But True’s mythic renown owed less to his ability to run than to his capacity to inspire. He was a free spirit who survived on cornmeal, beans and wild dreams, aloof to the allure of money and possessions. He lived in the remote Copper Canyons of northern Mexico to be near the reclusive Tarahumara Indians, reputed to be the greatest natural runners in the world.

His story was exuberantly molded into legend in the 2009 best-seller “Born to Run” by Christopher McDougall. Caballo Blanco, however private and self-effacing, was suddenly delivered to the world as a prophet, “the lone wanderer of the High Sierras.” To many, he represented the road not taken, a purer path, away from career, away from capitalism, away from the clock.

McDougall, himself a runner, was one of the dozens who had hurried to southwestern New Mexico to join the search, as had the actor Peter Sarsgaard, who was about to direct a movie based on the book. In just a few days, the Gila Wilderness had become a lodestone to a who’s who of ultramarathoners, athletes with loose limbs, lanky bodies and now a shared sense of dread.

“We’re thinking he could be lying out there hurt, unable to get help,” said the ultrarunner Luis Escobar, who had driven all night from California.

Several of these athletes were impatient with the authorities’ methodical search. The main footpaths had been scoured, but they wanted to venture onto the smaller elk trails and into the pockets and crannies of the cliffs.

Bemis, the rescue coordinator, was mildly annoyed: “This is a wilderness, not a walk in the park, and some of them might get lost. Then we’ll be looking for them, too.”

Among the most restless was Ray Molina, who led mountain bike tours through the Copper Canyons and was one of True’s closest friends.

Random Ray, some people called him. A nonstop talker, he was also a pack rat, collecting old bicycles, antique toys, manikins and bleached bones. Skeletal remains jounced about in his car.

Molina, 44, had not learned of the disappearance until Friday. He rushed to the Gila in his beat-up 1979 Mercedes with two friends, Jessica Haines and Dean Bannon. They were agreeable to joining the organized search. But by 10 on Saturday morning, they were among a handful yet to be assigned to a team.

The hell with this, Molina concluded. He and his friends lightened their backpacks of unnecessary gear and went off on their own, simply walking a short distance down the access road, crossing the Gila River and scurrying into the nearest arroyo.

This strategy, while not entirely random, was hardly well conceived. They were assisted only by a folded-up map and their own instincts and whims.

They rambled and they ran and they climbed. They called out, “Caballo!”

THE NAME MICAH TRUE was a confection, the first part plucked from the Bible, the second an homage to True Dog, a beloved mutt. Michael Randall Hickman was his given name, and he was raised in Northern California, the second of four children. His father was a Marine gunnery sergeant who later became a deputy sheriff and an insurance salesman.

The elder Hickmans were conservative Roman Catholics, but Mike’s devotions were to the counterculture of the late ’60s and early ’70s. His blond hair hung past his shoulders. Marijuana fluted through his head. So did mysticism. His reading appetites ranged from Hemingway to French philosophy.

He wandered the country, “just to make things happen,” he recalled later. His looks were fetching. One friend described him as “a lean Greek god in beachcomber garb.” Hickman lived for 10 months in a cave in Hawaii, shaking papayas from trees on Maui and running along island trails. He fell in love with a rich girl, he said, “whose eyes sparkled blue like the sky.” When she dumped him, it scuffed his heart.

To keep himself in pocket money, Hickman often chose unusual labor for a peaceable soul: prizefighting. A middleweight, he called himself the Gypsy Cowboy. His record in the ring, according to boxrec.com, was 9-11. He was knocked out nine times, although some of those defeats were dives taken for an easy payday, he said. Whoever the opponent, he tried to restrain his fists, inflicting “only the physical damage to get the job done, no more.”

Neill Woelk, a former sportswriter, remembers seeing him — his name now Micah True — in 1982, winning a fight on an undercard in Denver’s Rainbow Theater.

The boxer was nearing 30 at the time. “He didn’t look anything like a fighter, but he might be one of the best pure athletes I ever saw,” Woelk said, adding, “He didn’t have arms; he had cables.”

By then, True had moved to Boulder, Colo., at the base of the eastern slope of the Rockies. The city listed hard to the left. Sometimes with sarcasm, sometimes with affection, it was referred to as the People’s Republic of Boulder. At the same time, it was becoming the nation’s high-altitude capital for high-endurance training.

To earn a living, the prizefighter was now a self-employed furniture mover, hauling people’s belongings in a rattletrap pickup. He lived without electricity in a spare one-room cabin off Magnolia Road. He shared an outhouse.

Running had become his overwhelming passion, maybe even his addiction. He was a mountain runner, a different breed from folks who showed up by the thousands to run a breezy 10K. He preferred races with fewer people and wide-open terrain, less concerned with his times than the surrounding scenery.

He would get up early to run, then do a moving job, then run again. He was logging about 170 miles a week. Dan Bowers was a frequent companion. He recalled, “After we’d run, we’d eat a big meal, enough to bust a rib, and then Micah would look at me and say, ‘You want to do another 10?’ ”

True’s pattern was to remain in Boulder for six months, then, with winter coming, head south to the Guatemalan highlands, running the lush trails around Lake Atitlán. Villagers grew used to the sight of the loping gringo. He was a 6-footer with a long mane and big teeth. Children surrounded him when he stopped to buy bananas and tortillas. They named him El Caballo Blanco.

The White Horse was winning ultraraces in those days, like the 50-miler between Cheyenne and Laramie on the back roads of Wyoming. He was serious about competition, interested in re-engineering his body to get more out of his lungs and legs, pushing the boundaries of stamina.

Injuries began to slow him as he closed in on 40, but he eventually viewed these annoyances as a liberation. He started to care less about piling on the megamileage and more about finding challenging trails. Running was an exploration, inside and out, endorphins feeding his cerebral bliss.

He did still run the occasional race. In 1993, he entered one of his favorites, the Leadville Trail 100, a punishing 100-mile push through the icy streams and boulder-clogged slopes of the Rockies. The very up-and-down of it was a killer, the altitude as high as 12,600 feet. Runners generally needed 18 to 30 hours to finish.

That year, a promoter brought along a handful of peasants from Chihuahua, Mexico. They were short. Some looked like grandfathers. They wore blousy shirts and loincloths to the starting line, and on their feet were sandals they themselves had just made from old tires fished from the Leadville dump.

When the race began, these odd interlopers immediately fell to the rear and stayed there for 40 miles. Then they started steadily moving up, passing others, barely winded by the arduous climbs. The first two of them finished about an hour ahead of anyone else. The winner was 55 years old.

TRUE’S DISAPPEARANCE might have been something to shrug off at first. He sometimes liked to get lost in the wild, allowing only curiosity to steer his feet, bushwhacking his way through dense terrain. Geronimo, the Apache warrior, had used the Gila as a refuge, and he was one of True’s boyhood heroes.

But the runner knew the geography here too well to get hopelessly turned around, and besides, he had left behind his beloved sidekick Guadajuko, a stray he had rescued from a Mexican river. At times, True retreated from humans, even from civilization itself. But he would never abandon his dog.

Ray Molina understood True’s penchants and habits. “There’s a good chance he’s nowhere near a trail,” Molina said. He and his two friends looked elsewhere, climbing a ridge toward the Gila high country. The ascent was time-consuming, very steep in parts, the footing unreliable.

Hours later, all they had for their efforts was frustration. They wanted to avoid the beaten path but kept finding the tracks of other searchers and even met up with a few, including two on horseback and another pair with dogs.

Studying his map, Molina was intrigued by a squiggly blue line indicating a stream called Little Creek. He was in the sway of two hunches. One was that an injured man might head for water. The other was that this meandering creek emptied out of the canyon only a mile or so from the lodge where True had been staying. His friend might have used this stream as a shortcut.

“Has anyone been down that creek?” Molina kept asking.

The horsemen had ridden through the canyon a little ways but stopped. They knew the area well and warned Molina that the passage got pretty rough.

“Go ahead, try it,” one joked. “We’ll come looking for you tomorrow.”

It was already late afternoon, and Molina wondered if it was wise to chance this hike so close to dark. But he, Jessica Haines and Dean Bannon enjoyed egging each other on. Molina had known Bannon since the third grade. Unsettled between them were decades of debate about who was gutsier.

The creek was ankle deep in some spots, knee high in others, and about as wide as an automobile. They walked slowly because it was hard to do otherwise. The banks were narrow. The three would move over land on one side until they met an impassable thicket or an overhang from the steep canyon wall. Then they would look for the best spot to leap across the water.

They repeated this zigzag enough times to realize they may as well slosh through the creek itself. The bed was gravel and sand, but there were submerged rocks everywhere. It would have been easy to turn an ankle.

Haines, 33, works in the engine room of a ferry in Alaska. However dour the purpose of this trek, she was pleased to be in a place of such extraordinary beauty. The millenniums had intricately sculptured the canyon, and the clear stream that ran through it moved in a musical trickle. She could hear a gentle whoosh above as breezes traipsed through the treetops.

Haines was the first to spot a footprint, its outline in the mud beside the creek. They had been told True was wearing shoes with a pattern of triangles on the tread. But this print was faint and partly washed away.

They paused. They had already slogged through Little Creek for 45 minutes, and the sun was getting low. If they went much farther, they could be stuck for the night.

Still, they persisted, and 10 minutes later they found more footprints, and a few minutes after that, more again. These were better defined, and triangles were part of the design. They compared the length with their own shoes, measuring with a stick. True wore a size 11. These were about the right size.

Energized now, their hearts thumping, the three picked up the pace.

They were trotting, and each began finding more tracks.

They shouted back and forth. “Here’s one, and here’s another!”

Soon they were seeing so many they no longer bothered to call out.

MICAH TRUE HAD BECOME obsessed with the Tarahumara. What did they know about running that others did not? Were they some sort of superhumans?

Tarahumara was the Spanish name. They called themselves the Rarámuri, loosely translated as the running people. They had retreated into the massive canyons of the Sierra Madre centuries ago to escape the conquistadors.

Generation after generation, they traversed the mountains and ravines along tight footpaths. Freakish endurance was required to cover the immense distances. Some chasms in the land were deeper than the Grand Canyon.

To better understand these people, True readjusted the rhythms of his life in 1994, alternating between Boulder and the Copper Canyons, still a furniture mover for half the year but a student of the Rarámuri for the rest. He built a tiny home at the bottom of a canyon in the town of Batopilas, carrying rocks from the river valley to use as a foundation and erecting walls with cement and adobe.

“The man called horse,” as he sometimes referred to himself in written musings, was rapturous with the adventure. He described getting lost in his new surroundings, scaling a rock-faced mountain, water bottle in his teeth, buzzards overhead, “crawling on his belly like a reptile” while “pulling himself upward by grasping at plants.” The canyons were stupendous, with alpine forests in the high altitudes and subtropical jungle on the valley floor.

He was careful not to intrude on the Rarámuri. Relationships developed over time. The impoverished tribe believed in kórima, their word for sharing what they could spare. They sometimes left him tortillas and pinole, a porridge of crushed corn and water. He reciprocated in kind.

Like the Rarámuri, True now ran in sandals, delighting in the simple act of self-propulsion, bounding along the undulating trails like a Neolithic hunter. He called it “moving meditation.” His motto was “run free,” and he did.

Running was essential to the human experience, he had decided. Most people undervalued its importance. Running was not merely a sound cardiovascular choice in a fitness craze; it was an ancient art, part of mankind’s genetic imprint. Humans had survived across geological time because they could chase animals until the prey dropped from exhaustion.

The Rarámuri, then, did not possess any locomotive secrets. They simply retained the “genetic cellular memory” most human beings had forgotten.

“Every one of us used to be a long-distance runner,” True said.

But the Rarámuri were themselves unhinging from their ancestral past. Many of the running people no longer ran; they lived in towns and wore bluejeans and cowboy hats. Modernity now flooded into the canyons. Mining companies sent huge trucks down new roads. Marijuana thrived in the soil, and rival drug cartels were in a merciless war within the ravines.

True wanted to help the Rarámuri preserve their running heritage. In 2003, he organized a 29-mile race that was intended to be a festive celebration of local culture, a gathering of the Rarámuri from the caves and ranchos of the “mother mountains.”

To advertise it, True ran from canyon to canyon, handing out fliers and spouting enthusiasm. He hoped for a large turnout, but come race day only seven runners showed up. True finished fifth, ahead of two thirsty Rarámuri who allowed themselves to be diverted by a spectator with beer.

The event wasn’t all he had wanted, but it was a start. It became an annual ultramarathon race, and in 2006, True had an exciting brainstorm. He would entice American ultrarunners to the Rarámuri’s home turf. Highest on his wish list was Scott Jurek, the greatest of them all.

Organizing such a thing was difficult for a man living without a phone or electricity. True journeyed to the town of Creel, where there was a computer to borrow and a dial-up connection. He reached out through cyberspace.

As it turned out, Jurek was a metaphysical soul mate, another man who considered running a cherished legacy from primitive times. To him, racing the legendary Rarámuri in their own canyons sounded awesome.

Getting there, on the other hand, was no simple matter. Once across the border, it involved a relay of bus rides — the vehicles hugging the road through narrow switchbacks — and True was not much help with logistical advice. Seven Americans showed up, uncertain what to expect, and although they found the landscape breathtaking, the course itself was a brutal and twisting 47 miles of forbidding climbs and frightening descents.

Caballo Blanco gave each of his visitors the nickname of a spirit-animal — the deer, the bear, the young wolf, the snow hawk — and the race was held on a glorious Sunday. Crowds congregated in the town of Urique, where the race started and ended. Avid spectators risked their pesos with wagers.

First to finish was Arnulfo Quimare, the swiftest of the Rarámuri, and then came Jurek, six minutes behind. Though unused to defeat, the American acknowledged the winner with a gracious bow. The race is vividly described in “Born to Run.” McDougall, the author, not only witnessed it but also ran in it. He had his own abiding interest in the Rarámuri — and he had previously met the curious American called Caballo Blanco who lived among them.

Earlier, McDougall had an idea to write a book about four ultrarunners. But his time in the Copper Canyons pushed him toward an entirely different project. Here was a hidden tribe of superathletes who had “mastered the secret of happiness” and lived “as benignly as bodhisattvas.” Here was an American dwelling among them, a “mysterious loner with a fake name.”

This was the stuff of a mind-blowing book.

AT ONE POINT, the canyon around Little Creek gets even narrower, and at the same time becomes straighter. Molina, Haines and Bannon had been in the stream for 90 minutes when they saw something ahead that was blood red, a color out of harmony amid the shadings of greens and browns.

“Do you see that?” Molina asked.

He rushed ahead while Haines hesitated. She thought it could be a dead animal, and in Alaska she had been taught to be cautious when coming upon fresh kill.

Molina was not so heedful. He soon recognized that the patch of red was a shirt with limbs on either side. A surge of emotions pulsed through him. His first thought was that his old friend was alive if hurt.

But once nearer the body he knew instantly it was a corpse. True was lying face up, his eyes glossy, his jaw open. Flies were busy.

The others also forced themselves to look. True’s body was reclining on an outcropping of small rocks and boulders. His legs were in 10 inches of water, and his arms were against his chest, the right one down, the left one up. One of his shoes was off, and nearby was a plastic water bottle, two-thirds empty.

It appeared that True had taken a bad tumble at some point. There were abrasions on his legs and the backs of his arms. The middle finger of his left hand was bent and purplish. It looked to be broken.

“Oh, man,” Molina said softly, and he realized he was weeping.

The task now was to get the word out, but they had no radio. Nor did they know exactly where they were. They had no GPS device.

They discussed what to do. Perhaps someone should stay with the body while the others went back. But that seemed too spooky to contemplate further: out there, in the dark, alone with the body. Mountain lions were mentioned.

No, they decided, they would all go. Yet other images crept into their minds. Molina wondered if they should place rocks on the body to keep animals from dragging it off — either that or cover it up with reeds and branches.

But they decided this too was unwise. They shouldn’t contaminate the scene. The medical examiner would want things untouched.

So they turned back toward where they had entered the canyon.

And this time they ran as fast as they could.

“BORN TO RUN” BEGINS with McDougall, its author, going to Mexico’s Copper Canyons, which he calls “a kind of shorebound Bermuda Triangle known for swallowing the misfits and desperadoes who stray inside.” He hopes to find the “phantom” Caballo Blanco, who seems to be “a ghost among ghosts.”

For a while, some of True’s friends in Boulder were particularly fond of quoting that passage. He had been a well-known fixture in the city for 25 years. Now, when he would stop in at the Trident Cafe or the Mountain Sun Pub and Brewery, they would genially feign surprise, shocked by the presence of the phantom.

Becoming the central character in a best-selling book is a monumental life-changer, especially if it happens unwittingly to a man who made a sacrament of living simply. A thousand conflicting feelings eddied in his head.

True told people the book contained exaggerations and inaccuracies. For one, the Tarahumara lived no such idyllic life. Then he retreated from those criticisms, praising and thanking McDougall; then he alleged more flaws.

The book was flattering, surely. But that itself was a source of unease. True did not see himself as anywhere near so eccentric and amazing. He oftentimes felt two forces were in a tug of war for his identity: Was he the person inside his own skin or the person inside the pages of “Born to Run”?

Much of the book’s significance rested in its assertion that cushioned running shoes were a hazard to the human foot. But what made “Born to Run” a superb read was the story line in Mexico. Many readers wanted to meet the celebrated Caballo Blanco, and they seemed to expect a guru or a shaman or a fleet-footed saint. “I feel like I always have to live up to the expectations of the book,” True complained.

But fame was enjoyable as well. True may never have wanted the world to beat a path to his door, but now he encouraged people to follow him on Facebook. He spent hours online tending to his messages, either at the Boulder public library or in the municipal building in Urique, Mexico.

Within months of the book’s publication, two Facebook friends became love interests. One was Kati Bell, a runner who worked in corporate marketing. “I told him: ‘You’re a celebrity now. You can make money out of this,’ ” Bell said.

That was an intriguing notion, though not for his own sake but for the Rarámuri. The Copper Canyon Ultra Marathon was beginning to fulfill his grand vision. The number of participants was multiplying. There were cash prizes for the winners, and every finisher received 500 pounds of corn. True was not only reviving the running culture but also feeding the hungry.

The race needed infusions of cash to sustain itself, and he agreed to a small number of personal appearances, Bell said, although he was appalled when she suggested they hold dinners and charge $100 a head.

“Let people donate whatever they want,” he insisted.

True proved to be an amiable and amusing speaker. He needed no notes to tell his stories, although a few beers helped. He was shaving his head now, a look that made his face all the more striking, the large ears and lips, the protruding chin, the deep crow’s feet at the corners of his eyes.

Audiences were reliably friendly, won over well before he uttered word one. True would smile at them even in midjeremiad. “Long after we’re gone, long after greed blows everything up, the Rarámuri are still going to be subsisting,” he said. “They know how to survive, they know how to endure.”

A nonprofit group, Norawas de Rarámuri, was set up to handle donations. Every dollar would benefit the Rarámuri, as True demanded.

But were others willing to demonstrate the same selflessness? True was certain of his own integrity but deeply suspicious of everyone else’s.

What was McDougall doing with the profits from the book, True wanted to know. And what about Ted McDonald, Barefoot Ted, another memorable character from “Born to Run”? He had started a company that made minimalist sandals modeled after the huaraches worn by the Rarámuri.

“Running is not supposed to be about getting people to buy stuff,” True wrote in an e-mail to friends. “Running should be free, man, and the Rarámuri are being used to sell lots of stuff. What do they get out of it?”

Barefoot Ted often found True irritating. “I give back every year to the Copper Canyon, but Caballo equated any business with evil,” he said. “He did great things down there, but you ended up loving him and not quite liking him. I told McDougall, you’ve brought into being a new Frankenstein.”

That is hardly a prevailing view, but True could indeed be prickly and sharp-elbowed as well as warmhearted. His mantra for running was: easy, light and smooth. But off the trails he was an easily frazzled man living a newly frazzling life. The “whole notoriety thing,” as he called it, was useful for raising funds, but he was afraid of looking like a sellout at the same time.

To him, honesty was everything. He worried: Am I pretending to be something I’m not? Am I unfairly benefiting from someone else’s book?

But he continued with the public speaking gigs, usually at running stores.

Scott Leese, another of True’s cyberpals, was an “executive coach” in California who “specialized in the rapid transformation of people.” He too was smitten with the Caballo Blanco portrayed in the book and wanted him to reach a wider audience. Last year, Leese became his reticent friend’s agent, “though Micah hated that word because it really screamed establishment.”

Leese’s new client was often a headache. He despised anything corporate. He refused to consider endorsements. But finally, last summer, he agreed to attend an event hosted by Saucony, the shoe company, going on a trail run with some of its retailers and speaking at a dinner in Utah.

Then, in the fall, True consented to a trip to Sweden, Demark and Britain. In England, he spoke in small theaters or halls in London, York, Chester, Bristol and Birmingham. Admission cost 10 pounds, about $16.

All the while, the runner found reasons to bellyache. “Very high maintenance,” Leese said. But when the trip ended, True regarded it as a success. The audiences appreciated him, and he wanted to do more public speaking. He was close to a multiappearance deal with Saucony.

Micah True was making his peace with the “notoriety thing.”

NOT LONG AFTER Ray Molina and his friends came out of Little Creek, they saw three of the Mas Locos, the so-called crazy ones, which loosely includes anybody who has traveled into the Copper Canyon to run the big race.

“We found Micah,” Molina shouted.

“What?”

“We found him. He’s in the creek and he’s dead.”

They stood together for a few moments, awash in melancholy.

Two of the ultrarunners volunteered to go to the creek and watch over the body. One was Simon Donato, 35, a geologist from Calgary, Alberta. The other was Tim Puetz, 33, who had been a captain in the Army infantry in Afghanistan. “Never leave a comrade behind, dead or alive,” he was thinking. What if the body washed down the creek? This required “eyes on.”

While posted in Logar Province in Afghanistan, Puetz read “Born to Run” in two sittings, and it changed his life. He used to awaken at 4 a.m. and jog for a few hours along a two-mile circuit around the perimeter of his outpost. He would often think of that amazing guy in the book, Caballo Blanco, who “seemed to live without limits and go wherever life led him.” When it was time to leave the military, he e-mailed True, asking permission to run in the ultramarathon.

“You don’t need permission, just come,” True wrote back.

Puetz (pronounced Pits) had met Donato at the 2010 race. To them, Mas Locos felt like a brotherhood. And now there they were, scrambling up the trail to safeguard Caballo’s body. They were wearing only running gear, but Molina and his friends had given them fleece jackets, a nylon cover, two flashlights, a cigarette lighter and a couple of granola bars.

Puetz and Donato hit the water. They wanted to move quickly through the creek but were also afraid of overshooting the corpse in the waning light. Then they finally saw him, lying peacefully on his back, like a man who had stopped to relax.

They built a fire on the bank across the creek, using pine cones for kindling. Despite the flames, the chill insinuated itself through the drifting night air.

Later, they shared a granola bar and slid under the cover, sitting with their backs to True and the creek and the canyon wall behind it. They preferred to face the steep forest slope. If a bear or a mountain lion came darting out of the darkness, it would most likely come through those trees.

They figured to take turns all night, one man feeding the fire while the other slept. But then, near midnight, they heard whistles, and there was Ray Molina with several others. They had brought warm blankets and food.

In the morning, the corpse was put in a body bag, then maneuvered onto a light metal frame. It was carried through the dense, snaggy brush of the forest until the woods intersected a trail. Three pack animals were there waiting, and one of them immediately caught Puetz’s eye. It was a light-shaded palomino with a cream-colored mane.

“Are you kidding me?” he said. “They sent a white horse.”

THE 2012 COPPER CANYON Ultra Marathon, held March 4, was the biggest yet. More than 350 Rarámuri ran the tortuous course. Some were as old as 70, some barely in their teens. Many women ran in their traditional long skirts, the bright material swinging back and forth.

About 100 other Mexicans competed, as well as 80 foreigners. Three runners broke the course record. The winner was a Rarámuri. A runner from the Czech Republic came in second.

In the days before, True was on a pendulum of mood swings, happy with being the host and anxious about the responsibility. Was there enough water? What about medical support? The Rarámuri were arriving 20 and 30 at a time in cattle trucks. They needed food and places to sleep.

But not all the arrangements fell on True’s shoulders anymore. In many ways, the event was outpacing him. Public officials considered the race a signature municipal event that merited their co-management. Politicians made the welcoming speeches. Goldcorp, the big mining company, had been enlisted by the municipality of Urique as a sponsor.

At times, True wished it were again just him running through the mountains with a handful of the Rarámuri. But mostly he was elated. These were tough times; a drought was in its second year, and the runners in the ultramarathon were rewarded with a voucher for 110 pounds of corn for every 10 miles they completed.

The race was the best of True’s good deeds. He described himself in the third person, all at once modest and grandiose: “Caballo Blanco is no hero. Not a great anything. Just a Horse of a little different color dancing to the beat of a peaceful drum and wanting to help make a little difference in some lives.”

The day after the race, he contentedly sat at a table by the municipal building handing out the valuable vouchers. The line stretched so long it took two hours to finish the paperwork. He and his charity gave away $40,000 in food.

On March 6, True left the canyons in his 25-year-old Nissan truck, driving with his dog, Guadajuko, and his girlfriend, Maria Walton, 50. They had been a couple for about two years. She too had found him on Facebook.

A divorcée with three grown children, Walton was the general manager of a large restaurant in Phoenix. She was as reliably even-tempered as True was mercurial. The Mas Locos generally agreed: Maria was an infusion of love and serenity into Caballo’s life. He called her by the spirit name La Mariposa, the butterfly.

True spent two weeks in Phoenix, then drove east with the dog to the Gila Wilderness in southwestern New Mexico, one of his favorite retreats. His friends Dean and Jane Bruemmer own a small lodge there. He sometimes stayed with them, although other times he camped out. Either way, in the mornings he used their wireless Internet connection. He remained compulsive about reading his e-mail.

“Life was going good for Micah; actually, life was going great,” Jane Bruemmer said. She had been unsure how well he was handling his sudden starburst of fame. “He didn’t seek it or need it, but he was using it now to fund his favorite cause,” she said. “He had an agent.” She found that so astonishing she needed to repeat it with more inflection: “Micah True had an agent!”

“Born to Run” was being made into a movie. The business deal did not involve True, and for a while he thought: Here it comes again. The film will bring as much upheaval into my life as the book. Sarsgaard — the director and co-author of the script — had warned him that no one watches a two-hour movie about himself and comes away thinking, that’s me up there.

True thought things had also taken an amusing karmic twist. McDougall, not him, was going to be the movie’s main character, and after reading a draft of the script, the book’s author, in an e-mail to True, called it “ridiculous” and said his “high expectations for the movie had plummeted.”

True took satisfaction in that. Now McDougall would find out how it felt to be defined by someone else. In an e-mail sent to Sarsgaard on March 26, he wrote, “As we know, I would have much liked to at least proofread, fact-check, and/or co-write what” McDougall said about him in the book. “Soooooo....... It is hard to feel toooo sorry for him.”

True spent much of that night writing messages, but he was up early the next day. Dean Bruemmer made him blueberry pancakes. True said he was going on a 12-mile run but leaving Guadajuko behind. The dog had sore paws from their jaunt the day before.

Caballo Blanco left the lodge at about 10 a.m. He was seen along State Highway 15. The sun was a hot yellow beam when he entered the wilderness.

MICAH TRUE’S CORPSE, encased in a body bag and draped over a brown mule, was taken through the forest and out to the main trailhead in midafternoon on Sunday, April 1. Maria Walton ran up a slope to meet it, calling out, “I love you,” and kissing the end of the bundle that appeared to be the feet.

Just then, a heavy wind began to blow. Dirt spun in the air. A hearse had been parked in an adjacent lot since morning, and the driver, dressed in a coat and tie, looked away to shield his eyes.

The mule was slowly led to the vehicle, and the body bag was lifted through the open door at the rear. Walton insisted that Guadajuko be permitted a farewell, cradling the dog in her arms and taking him over. “We’re going to see Daddy, your best buddy,” she said, sobbing.

Ray Molina, haggard and exhausted, hugged Walton and then leaned against his old Mercedes and talked about finding the corpse. “Micah was bloodied up, so I think he took a tumble and then a hypothermic night did him in,” he said.

Mike Barragree, an investigator for the state medical examiner’s office, had gone with the team that reclaimed the body. He speculated that “some sort of cardiac event” was the likely cause of death, and that turned out to be correct: idiopathic cardiomyopathy, a heart ailment.

The search and recovery mission was finally over. The remembrances had already begun. The evening before, Walton and Scott Leese and many of the Mas Locos hung out at a campground that also had a few small cottages. The moon was a half-circle. The stars were abundant. Someone had thought to buy beer.

For them, this was a requiem for a dead friend. They ate tortillas and eggs and canned stew, heating the food on an old white stove and subduing their sorrow with laughter. They each had a favorite Caballo Blanco story to tell, or two or three. The past flooded into the present.

Above all, their friend wanted to be authentic, they said, and no one could doubt that he had been. This was no small thing.

His death was terribly sad, and yet there was also perfection about it.

Micah True died while running through a magnificent wilderness, and then many of his closest friends came together to search for him, stepping through the same alluring canyons and forests and streams, again and again calling out his name.